DE102004050747A1 - Coating compositions containing adducts with alkoxysilane functionality - Google Patents

Abstract

The invention relates to coating compositions comprising (A) at least 50% by weight, based on the content of nonvolatile substances in the coating composition, of at least one compound (A1) having at least one reactive group of the formula I DOLLAR A -NR-C (O) - N- (X-SiR''x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m DOLLAR A with DOLLAR AR = hydrogen, alkyl, cycloalkyl, aryl or aralkyl wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, wherein Ra = alkyl, cycloalkyl, aryl or aralkyl, DOLLAR AR '= hydrogen, alkyl, cycloalkyl, aryl or aralkyl, wherein the carbon chain by not adjacent oxygen, sulfur or NRa groups may be interrupted, DOLLAR AX, X '= linear and / or branched alkylene or cycloalkylene radical having 2 to 20 carbon atoms, DOLLAR A R' '= alkyl, cycloalkyl, aryl or aralkyl, wherein the Carbon chain can be interrupted by non-adjacent oxygen, sulfur or NRa groups, DO LLAR A n = 0 to 2, DOLLAR A m = 0 to 2, DOLLAR A m + n = 2 and DOLLAR A x, y = 0 to 2, DOLLAR A (B) a catalyst for the cross-linking of -Si (OR ' ) 3-x (y) units and DOLLAR A (C) an aprotic solvent or a mixture of aprotic solvents.

Description

The The present invention relates to thermally curable high scratch resistant coating compositions based on aprotic solvents containing adducts with alkoxysilane functionality, wherein the adducts at least have a urea group.

Solvent-based Coating compositions containing binders based on poly (meth) acrylates, which have lateral and / or terminal alkoxysilane, for example from the patents or patent applications US-A-4,043,953, US-A-4,499,150, US-A-4,499,151, EP-A-0 549 643 and WO-A-92/20643. These Coating agents described under catalysis of Lewis acids and optionally in the presence of small amounts of water with formation Hardened by Si-O-Si networks. The Coating agents are used, inter alia, as clearcoats in OEM constructions used. Although such clearcoats already have a high scratch resistance and have a relatively good weather resistance, they have Deficits that apply as heavy-duty OEM clearcoats difficult.

So are due to the relatively broad molecular weight distribution of Poly (meth) acrylates having alkoxysilane groups in general in the Clearcoats solid contents less than 50% by weight. At higher proportions are the paints due to their high viscosity only difficult to process. Furthermore, when curing in Competition to the desired ones Si-O-Si network points by transesterification of the -Si (O-alkyl) 3 groups with Ester units of the adjacent alkyl (meth) acrylate comonomer units undesirable Si-O-C-network points form, which are hydrolysis-labile and to a reduced chemical resistance lead the resulting coating. Because the heavy duty OEM clearcoats the highest possible weatherability It is important that the poly (meth) acrylate networks compared to polyurethane networks a reduced weather resistance exhibit.

In EP-A-0 267 698 becomes solvent-containing Coating described which as binder components (1) crosslinkable adducts with alkoxysilane groups, obtainable by successive reaction of polyisocyanates with hydroxyalkyl (meth) acrylates (Michael reaction) and then with aminoalkylalkoxysilanes, and (2) Poly (meth) acrylates, the lateral and / or terminal alkoxysilane groups have included. The well formed in the Michael reaction accessible Lead amine groups in the adducts to a reduction in the water resistance of the cured coatings. Furthermore you can through these amine groups in the curing process Reaction with the -Si (OR) 3 groups form Si-N-C network points which are hydrolysis-labile are and resulting in a reduced chemical resistance of the resulting Lead coating. Regarding the adverse effect of the alkoxysilane-functionalized Poly (meth) acrylates in the coating agent applies the above.

US Pat No. 4,598,131 describes solvent-containing Coating compositions comprising crosslinkable adducts with alkoxysilane groups, available by successive reaction of tetraalkyl orthosilicate with amino alcohols and then with polyisocyanates. Such adducts are synthesis-related undesirable Si-O-C or Si-N-C network points which are hydrolysis-labile and to a reduced chemical resistance of the resulting Lead coating.

In EP-A-0 571 073 becomes solvent-containing Coating described which as binder components (1) crosslinkable adducts of polyisocyanates with more than one tertiary isocyanate group and aminoalkylalkoxysilanes and (2) poly (meth) acrylates, the lateral and / or terminal alkoxysilane groups. The tertiary Isocyanate groups can the elasticity after curing of the coating agent obtained network and thus lead to a deteriorated gloss after scratching. Furthermore Such polyisocyanates are expensive to prepare and only conditionally available. Regarding the adverse effect of the alkoxysilane-functionalized Poly (meth) acrylates in the coating agent applies the above.

DE-A-102 37 270 includes Coating composition comprising crosslinkable adducts of isocyanatomethylalkoxysilanes and polyols. The isocyanatomethylalkoxysilanes used in the synthesis are highly toxic and therefore in usual Production process only conditionally usable. Also these coating agents especially when used as automotive clearcoat still Deficits in the surface properties, in particular after loads, such as washing, on.

Task and solution

task It has been the object of the present invention to provide coating compositions, in particular for OEM clearcoats, for disposal which do not have the disadvantages of alkoxysilane-functionalized Poly (meth) acrylates, in particular the problematic processability at high solids contents and the unwanted Formation of Si-O-C network points, which are hydrolysis-labile and have a reduced chemical resistance lead the resulting coating. It was still a task of the invention to provide coating compositions which form a highly weather-stable network, which is highly dependent on polyurethane and / or polyurea units, the undesirable formation of Si-O-C- and of Si-N-C network points, as far as possible suppressed. In particular, should the coatings are highly scratch resistant and in particular one have high gloss retention after scratching. in particular should the coatings and coatings, especially the clearcoats, also produce in layer thicknesses> 40 microns leave without causing stress cracks. This is an essential one requirement for the use of coatings and coatings, in particular of clearcoats, in which technologically and aesthetically very demanding Automotive OEM (OEM) area. They have to Above all, have a particularly high wash resistance, which is in the for the Practice relevant AMTEC-Waschstraßentest by a residual gloss (20 °) after Cleaning according to DIN 67530> 70% makes the initial gloss noticeable.

Furthermore the new coating agents are easy and very reproducible be manufacturable and while the paint application no ecological To cause problems.

• (A) mindestens 50 Gew.-%, bezogen auf den Gehalt an nichtflüchtigen Substanzen im Beschichtungsmittel, einer Verbindung (A1) mit mindestens einer reaktiven Gruppe der Formel I -NR-C(O)-N-(X-SiR''x(OR')3-x)n(X'-SiR''y(OR')3-y)m (I)mit R = Wasserstoff, Alkyl, Cycloalkyl, Aryl oder Aralkyl, wobei die Kohlenstoffkette durch nicht benachbarte Sauerstoff-, Schwefel- oder NRa-Gruppen unterbrochen sein kann mit Ra = Alkyl, Cycloalkyl, Aryl oder Aralkyl R' = Wasserstoff, Alkyl oder Cycloalkyl, wobei die Kohlenstoffkette durch nicht benachbarte Sauerstoff-, Schwefel- oder NRa-Gruppen unterbrochen sein kann, X,X' = linearer und/oder verzweigter Alkylen oder Cycloalkylenrest mit 2 bis 20 Kohlenstoffatomen, R'' = Alkyl, Cycloalkyl, Aryl oder Aralkyl, wobei die Kohlenstoffkette durch nicht benachbarte Sauerstoff-, Schwefel- oder NRa-Gruppen unterbrochen sein kann, n = 0 bis 2, m = 0 bis 2, m + n = 2, sowie x,y = 0 bis 2,
• (B) einen Katalysator für die Vernetzung der -Si(OR')3-x(y)-Einheiten, und
• (C) ein aprotisches Lösemittel oder ein Gemisch von aprotischen Lösemitteln.

Accordingly, coating agents were found containing

• (A) at least 50 wt .-%, based on the content of nonvolatile substances in the coating composition, of a compound (A1) having at least one reactive group of the formula I. -NR-C (O) -N- (X-SiR "x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m (I) where R = hydrogen, alkyl, cycloalkyl, aryl or aralkyl, where the carbon chain can be interrupted by nonadjacent oxygen, sulfur or NRa groups with Ra = alkyl, cycloalkyl, aryl or aralkyl R '= hydrogen, alkyl or cycloalkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, X, X '= linear and / or branched alkylene or cycloalkylene radical having 2 to 20 carbon atoms, R "= alkyl, cycloalkyl, aryl or aralkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, n = 0 to 2, m = 0 to 2, m + n = 2, and x, y = 0 to 2,
• (B) a catalyst for cross-linking the -Si (OR ') 3-x (y) units, and
• (C) an aprotic solvent or a mixture of aprotic solvents.

in the In view of the prior art, it was surprising and for the expert unpredictable that the Problems underlying the present invention with the aid of the coating agent of the invention solved could become.

The Component of the invention (A) can be made very easily and very reproducible be and prepares in the paint application no significant toxicological and ecological Problems.

The Coating compositions of the invention were easy and very reproducible and could produce when used in liquid State to solids contents> 40 wt .-%, preferably> 45 wt .-%, in particular> 50 wt .-% adjusted without doing so their excellent transportability, storage stability and processability, especially their applicability, were affected.

The coating compositions of the invention provided new coatings and coatings, spe For example, clearcoats that were highly scratch-resistant. Outstanding is the chemical resistance of the coatings. Furthermore, the coatings and coatings according to the invention, especially the clearcoats, could also be produced in layer thicknesses> 40 μm without stress cracks occurring. For this reason, the coatings and coatings according to the invention, in particular the clearcoats, could be used in the technologically and aesthetically particularly demanding field of automotive OEM finishing. They were characterized in particular by a particularly high wash resistance and Kratzfestigleit, which was based on the relevant for practice AMTEC-Waschstraßentests by a residual gloss (20 °) after cleaning according to DIN 67530> 70% of the initial gloss.

description the invention

Component (A) of coating agent

The component (A) according to the invention contains at least 50% by weight, based on the content of non-volatile substances in the coating agent, of a compound (A1) having at least one reactive group of the formula I. -NR-C (O) -N- (X-SiR "x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m (I) With
R = hydrogen, alkyl, cycloalkyl, aryl or aralkyl, where the carbon chain may be interrupted by nonadjacent oxygen, sulfur or NRa groups, where R a = alkyl, cycloalkyl, aryl or aralkyl,
R '= hydrogen, alkyl, or cycloalkyl, where the carbon chain may be interrupted by nonadjacent oxygen, sulfur or NRa groups, R' being preferably alkyl having 1 to 6 carbon atoms, more preferably methyl and / or ethyl,
X, X '= linear and / or branched alkylene or cycloalkylene radical having 2 to 20 carbon atoms, where X, X' are preferably alkylene having 2 to 6 carbon atoms, particularly preferably alkylene having 2 to 4 carbon atoms,
R '' = alkyl, cycloalkyl, aryl or aralkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, wherein R "is preferably alkyl having 1 to 6 carbon atoms, more preferably methyl and / or ethyl is
n = 0 to 2,
m = 0 to 2,
m + n = 2, as well
x, y = 0 to 2, preferably x = 0.

The compound (A1) according to the invention is preferably prepared by reacting at least one di- and / or polyisocyanate (PI) with at least one aminosilane of the formula II: HN- (X-SiR''x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m (II), wherein the substituents and the indices have the abovementioned meaning.

Particularly preferred aminosilanes (II) are bis (2-ethyltrimethoxysilyl) amine, bis (3-propyltrimethoxysilyl) amine, bis (4-butyltrimethoxysilyl) amine, bis (2-ethyltriethoxysilyl) amine, bis (3-propyltrimethoxysilyl) amine and / or bis (4-butyltriethoxysilyl) amine. Very particular preference is given to bis (3-propyltrimethoxysilyl) amine. Such aminosilanes are, for example, under the brand name of the Fa DYNASILAN. DEGUSSA or Silquest ^® from. OSI.

Preferred di- and / or polyisocyanates PI for the preparation of the compound (A1) are known per se known substituted or unsubstituted aromatic, aliphatic, cycloaliphatic and / or heterocyclic polyisocyanates. Examples of preferred polyisocyanates are: 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, p-phenylene diisocyanate, biphenyl diisocyanates, 3,3'-dimethyl-4 , 4'-diphenylene diisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, 2,2,4-trimethylhexane-1,6-diisocyanate, isophorone diisocyanate, ethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1, 3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, methylcyclohexyl diisocyanate, hexahydrotoluene-2,4-diisocyanate, hexahydrotoluene-2,6-diisocyanate, hexahydrophenylene-1,3-diisocyanate, hexahydrophenylene-1, 4-diisocyanate, perhydrodiphenylmethane-2,4'-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (Desmodur ^® W of Fa. Bayer AG), tetramethylxylyl diisocyanates (eg TMXDI ^® from. American Cyanamid), and mixtures of the aforementioned polyisocyanates. Further preferred Polyisocyanates are the biuret dimers and the isocyanurate trimers of the aforementioned diisocyanates.

Especially preferred polyisocyanates PI are hexamethylene-1,6-diisocyanate, isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate, their biuret dimers and / or isocyanurate trimers.

In a further embodiment The invention relates to the polyisocyanates PI polyisocyanate prepolymers with urethane structural units, wel che by reaction of polyols with a stoichiometric excess of the aforementioned Polyisocyanates are obtained. Such polyisocyanate prepolymers are described for example in US-A-4,598,131.

All particularly preferred compounds (A1) are: reaction products of hexamethylene-1,6-diisocyanate and isophorone diisocyanate, and / or their isocyanurate trimers with bis (3-propyltrimethoxysilyl) amine.

The Reaction of the polyisocyanates with the aminosilanes is preferably carried out in an inert gas atmosphere Temperatures of maximum 100 ° C, preferably of not more than 60 ° C.

The resulting compound (A1) according to the invention comprises at least a structural unit of the aforementioned formula (I), according to the invention preferred Manufacturing method are preferably at least 90 mol% of the isocyanate groups of the polyisocyanate PI with the aminosilanes (II), more preferably at least 95 mol%, converted into structural units (I).

Of the The proportion of the compound (A1) in the coating composition of the invention is at least 50 Wt .-%, based on the content of nonvolatile substances in the coating composition, preferably at least 60% by weight, more preferably at least 70% Wt .-%.

Component (B) of coating agent

When Catalysts (B) for the cross-linking of the -Si (OR ') 3-x (y) units can known compounds are used. examples are Lewis acids (Electron deficient compounds), such as tin naphthenate, Tin benzoate, stannous octoate, stannous butyrate, dibutyltin dilaurate, dibutyltin diacetate, Dibutyltin oxide, lead octoate.

As catalysts, metal complexes with chelating ligands are preferably used. The chelating ligand-forming compounds are organic compounds having at least two functional groups capable of coordinating with metal atoms or ions. Typically, these functional groups are electron donors which donate electrons to metal atoms or ions as electron acceptors. There are basically all organic compounds of the type mentioned suitable, as long as they do not adversely affect the crosslinking of the curable compositions of the invention to cured compositions of the invention or even completely prevent. For example, the aluminum and zirconium chelate complexes as described, for example, in US Pat US 4,772,672 A , Column 8, line 1 to column 9, line 49, can be used as catalysts. Particularly preferred are aluminum, zirconium, titanium and / or boron chelates, such as, for example, aluminum ethyl acetoacetate and / or zirconium ethyl acetoacetate.

Farther Particularly preferred are aluminum, zirconium, titanium and / or boron alcoholates and / or Esters.

Furthermore particularly preferred as component (B) are nanoparticles. Such Nanoparticles are preferably at least partially crosslinked -Si (OR ') 3-x (y) units built into the network points.

Preferably be the nanoparticles from the group consisting of metals and Compounds of metals, preferably compounds of metals, selected.

Preferably become the metals of the third and fourth main group, the third to sixth as well as the first and second subgroup of the Periodic table of the elements and the lanthanides, and preferred from the group consisting of boron, aluminum, gallium, silicon, Germanium, tin, zinc, titanium, zirconium, hafnium, vanadium, niobium, tantalum, Molybdenum, Tungsten and cerium, selected. In particular, aluminum, silicon, titanium and / or zirconium are used.

Preferably if the compounds of the metals are oxides, oxide hydrates, Sulfates, hydroxides or phosphates, in particular oxides, oxide hydrates and hydroxides. Very particular preference is given to boehmite nanoparticles.

Preferably the nanoparticles have a primary particle size <50, preferably 5 to 50, in particular 5 to 30 nm.

The Catalonater component (B) is preferably used in proportions of 0.01 up to 30% by weight, particularly preferably in proportions of 0.1 to 20% by weight, based on the non-volatile Constituents of the coating composition according to the invention, used.

Component (C) and other components of the coating agent

As component (C) according to the invention, aprotic solvents are suitable which are chemically inert in the coating composition compared to the components (A) and (B) and which also do not react with (A) and (B) during the curing of the coating agent. Examples of such solvents are aliphatic and / or aromatic hydrocarbons such as toluene, xylene, solvent naphtha, Solvesso 100 or hydrosol ^® (Fa. A-RAL), ketones such as acetone, methyl ethyl ketone or methyl amyl ketone, esters such as ethyl acetate, butyl acetate, pentyl acetate or ethyl ethoxypropionate , Ethers or mixtures of the abovementioned solvents. The aprotic solvents or solvent mixtures preferably have a water content of not more than 1% by weight, more preferably not more than 0.5% by weight, based on the solvent. In a preferred embodiment of the invention, a mixture of components (A) and (C) is prepared in the preparation of the Beschich first agent, which is mixed in a further step with the other components of the coating composition of the invention.

In a further embodiment the invention are used as component (D) further binders, which with the Si (OR) 3 groups the component (A) and / or with itself, optionally with catalysis Component (B), can form network points. For example, as Component (D) Oligomerizates or polymers with Si (OR) 3 groups can be used, such as in the already mentioned patent (application) s US-A-4,499,150, US-A-4,499,151 or EP-A-0 571 073 mentioned poly (meth) acrylates. However, that will be such components (D) are used only in amounts such that the polyurethane or polyurea character of the network and thus the high weathering stability of the cured coating preserved. In general, such poly (meth) acrylates with Si (OR) 3 groups in proportions of up to 40 wt .-%, preferably from up to 30 wt .-%, particularly preferably up to 25 wt .-%, based on the non-volatile Components of the coating agent used.

Prefers as component (D), aminoplast resins and / or epoxy resins are usable. The usual ones come and known aminoplast resins, their methylol and / or Methoxymethyl groups z. T. by means of carbamate or allophanate groups can be defunctionalized. Crosslinking agents of this type are described in the patents US-A-4 710 542 and EP-B-0 245 700 as well as in the article by B. Singh and Employee "carbamylmethylated Melamine, Novel Crosslinker for the Coatings Industry "in Advanced Organic Coatings Science and Technology Series, 1991, Volume 13, pages 193 to 207, described. Particularly preferred components (D) are epoxy resins, which prefers to itself under the catalysis of the component (B) react, more preferably aliphatic epoxy resins which have a high weathering stability. Such epoxy resins are, for example, in the monograph of B. Ellis "Chemistry and Technology of Epoxy Resins "(Blackie Academic & Professional, 1993, pages 1 to 35).

In usually the components (D) in proportions of up to 40 wt .-%, preferably of up to 30% by weight, more preferably of up to 25 Wt .-%, based on the non-volatile Components of the coating agent used. In selecting of components (D) it should be noted that when curing the coating agent not or only to a very limited extent hydrolysis-labile Si-N-C and / or Si-O-C network points formed become.

• – insbesondere UV-Absorber;
• – insbesondere Lichtschutzmittel wie HALS-Verbindungen, Benztriazole oder Oxalanilide;
• – Radikalfänger;
• – Slipadditive;
• – Polymerisationsinhibitoren;
• – Entschäumer;
• – Reaktivverdünner, wie sie aus dem Stand der Technik allgemein bekannt sind, welche bevorzugt nicht mit den -Si(OR)3-Gruppen der Komponente (A) unter der Ausbildung von -Si-O-C- und/oder -Si-N-C-Netzpunkten reagieren.
• – Netzmittel wie Siloxane, fluorhaltige Verbindungen, Carbonsäurehalbester, Phosphorsäureester, Polyacrylsäuren und deren Copolymere oder Polyurethane;
• – Haftvermittler wie Tricyclodecandimethanol;
• – Verlaufmittel;
• – filmbildende Hilfsmittel wie Cellulose-Derivate;
• – von der Komponente (B) verschiedene Füllstoffe wie beispielsweise Nanopartikel auf der Basis von Siliziumdioxid, Aluminiumoxid oder Zirkoniumoxid; ergänzend wird noch auf das Römpp Lexikon »Lacke und Druckfarben« Georg Thieme Verlag, Stuttgart, 1998, Seiten 250 bis 252, verwiesen;
• – Rheologiesteuernder Additive wie die aus den Patentschriften WO 94/22968, EP-A-0 276 501, EP-A-0 249 201 oder WO 97/12945 bekannten; vernetzte polymere Mikroteilchen, wie sie beispielsweise in der EP-A-0 008 127 offenbart sind; anorganische Schichtsilikate wie Aluminium-Magnesium-Silikate, Natrium-Magnesium- und Natrium-Magnesium-Fluor-Lithium-Schichtsilikate des Montmorillonit-Typs; Kieselsäuren wie Aerosile; oder synthetische Polymere mit ionischen und/oder assoziativ wirkenden Gruppen wie Polyvinylalkohol, Poly(meth)acrylamid, Poly(meth)acrylsäure, Polyvinylpyrrolidon, Styrol-Maleinsäureanhydrid- oder Ethylen-Maleinsäure-anhydrid-Copolymere und ihre Derivate oder hydrophob modifizierte ethoxylierte Urethane oder Polyacrylate;
• – und/oder Flammschutzmittel.

In addition, the coating composition according to the invention may comprise at least one customary and known coating additive in effective amounts, ie in amounts preferably up to 30% by weight, more preferably up to 25% by weight and in particular up to 20% by weight, based in each case on the nonvolatile constituents of the coating agent. Examples of suitable paint additives are:

• - in particular UV absorber;
• In particular light stabilizers, such as HALS compounds, benzotriazoles or oxalanilides;
• - radical scavengers;
• - panty additives;
• - polymerization inhibitors;
• Defoamer;
• Reactive diluents, as are well known in the art, which preferably do not react with the -Si (OR) 3 groups of component (A) to form -Si-OC and / or -Si-NC network points react.
• Wetting agents such as siloxanes, fluorine-containing compounds, carboxylic acid monoesters, phosphoric esters, polyacrylic acids and their copolymers or polyurethanes;
• - adhesion promoters such as tricyclodecanedimethanol;
• - leveling agent;
• - film-forming aids such as cellulose derivatives;
• - Of the component (B) different fillers such as nanoparticles based on silica, alumina or zirconia; in addition, reference is still made to the Römpp Lexikon "Paints and Printing Inks" Georg Thieme Verlag, Stuttgart, 1998, pages 250 to 252;
• Rheology control additives such as those known from the patents WO 94/22968, EP-A-0 276 501, EP-A-0 249 201 or WO 97/12945; crosslinked polymeric microparticles such as disclosed in EP-A-0081227; inorganic phyllosilicates such as aluminum-magnesium silicates, sodium magnesium and sodium magnesium fluorine lithium phyllosilicates of the montmorillonite type; Silicas such as aerosils; or synthetic polymers having ionic and / or associative groups such as polyvinyl alcohol, poly (meth) acrylamide, poly (meth) acrylic acid, polyvinylpyrrolidone, styrene-maleic anhydride or ethylene-maleic anhydride copolymers and their derivatives or hydrophobically modified ethoxylated urethanes or polyacrylates ;
• And / or flame retardants.

In a further embodiment The coating composition according to the invention can still be used in the invention further pigments and / or fillers contain and for the production of pigmented Topcoats serve. The used for it Pigments and / or fillers are known in the art.

There from the coating compositions of the invention prepared coatings according to the invention even on already hardened Electrocoating, surfacer, Basecoats or usual and excellent adhesion to known clearcoats, they are suitable awarded in addition to the use in the automotive series (OEM) painting for the Car refinish or scratch resistant equipment from exposed areas of painted automobile bodies.

The Application of the coating compositions of the invention can through all the usual Application methods, such as Spraying, doctoring, painting, casting, diving, Soak, trickle or rolling done. In this case, the substrate to be coated as such rest, wherein the application device or system is moved. However, the substrate to be coated, in particular a Coil, to be moved, the application system relative to the substrate resting or moving in an appropriate manner.

Preferably Spray application methods are used, such as compressed air spraying, airless spraying, High rotation, electrostatic spray application (ESTA), if necessary connected with hot spray application such as hot air hot spraying.

The curing the applied coating composition according to the invention can be done after a certain rest period. The rest period is for example for the course and degassing of the paint layers or for evaporation of fleeting Ingredients such as solvents. The rest period may be due to the application of elevated temperatures and / or be supported and / or shortened by a reduced air humidity, if there are no damages or changes enter the paint layers, such as a premature complete networking.

The thermal curing the coating agent has no special features on, but according to the usual and known methods such as heating in a convection oven or irradiation with IR lamps. Here, the thermal curing can also be done gradually. Another preferred curing method is the cure with near infrared (NIR radiation).

advantageously, the thermal curing takes place at a temperature of 50 to 200 ° C, more preferably 60 to 190 ° C and in particular 80 to 180 ° C while a time of 1 minute to 5 hours, more preferably 2 minutes up to 2 hours and especially 3 minutes to 90 minutes.

The Coating compositions of the invention deliver new hardened Coatings, in particular coatings, especially clearcoats, Molded parts, especially optical molded parts, and self-supporting films, the highly scratch-resistant and in particular resistant to chemicals and weathering are. In particular, the coatings and coatings according to the invention, especially the clearcoats, also in layer thicknesses> 40 μm, without stress cracks occur.

The Coating compositions of the invention are therefore ideal as a decorative, protective and / or effective, highly scratch resistant coatings and finishes of Bodies of means of transport (in particular motor vehicles, like motorcycles, Buses, trucks or cars) or parts thereof; of buildings in the interior and outdoor area; of furniture, Windows and doors; of plastic moldings, in particular CDs and windows; of industrial Small parts, of coils, containers and packaging; of white goods; of films; of optical, electrical and mechanical components as well as glass hollow bodies and objects of the daily Needs. In particular, the coating compositions of the invention and Lacquers, in particular the clearcoats, in the technological and aesthetically special demanding field of automotive OEM (OEM). Particular preference is given to the coating compositions of the invention in multi-stage coating method used, in particular at Method in which an optionally precoated substrate first a pigmented base lacquer layer and then a layer with the Coating compositions of the invention be applied. Such methods are described, for example, in US-A-4,499,150 described.

there are characterized by a particularly high level of chemical and weather resistance as well as a very good wash line resistance and scratch resistance, based on the relevant for the practice AMTEC-Waschstraßentests through a residual shine (20 °) after purification according to DIN 67530> 70%, preferably> 80%, of the initial gloss is occupied.

Production Example 1 - Production a suitable catalyst (component (B))

Around sufficient curing to ensure the clearcoat was first made a suitable catalyst. These were added to 20.43 parts by weight Aluminum sec-butylate in a round bottom flask slowly at room temperature Added 13.01 parts by weight of ethyl acetoacetate, stirring and chilled has been. Subsequently the reaction mixture was stirred for a further 1 h at room temperature.

Production Example 2 - Production a silanated diisocyanate (HDI with bisalkoxysilylamine) (component (A1))

In a three-neck glass flask equipped with a reflux condenser and a thermometer, 30.4 parts of trimerized hexamethylene diisocyanate (HDI) (Basonat HI 100) and 15.2 parts Solventnaphta submitted. Under nitrogen blanketing and stirring 54.4 parts of bis [3- (trimethoxysilyl) propyl] amine (Silquest A 1170) so metered in, the 50 ° C not exceeded become. After the end of the dosage, the reaction temperature at Kept at 50 ° C. The complete Blocking is detected by means of the titration described above.

The thus obtained blocked isocyanate is more at room temperature than one month at 40 ° C stable on storage and could after addition of an aluminum catalyst as 2 K clear coat can be applied.

Formulation of scratch-resistant and chemical resistant coating materials

to Formulation of highly scratch-resistant and chemical-resistant coating agents were 90 wt .-% of the diisocyanate adduct described in Preparation 2 (A1) with 10 wt .-% of the catalyst described in Preparation 1 (B) offset. The resulting coating agent was applied and at 140 ° C for 22 minutes baked. The scratch resistance of the surfaces of the resulting coating 2 was examined by means of the steel wool test. The chemical resistance was examined using the BART test.

Table 1 - Properties of the coating produced with the efrindungsgemäßen coating

to execution of the steel wool scratch test was a hammer according to DIN 1041 (weight without stem: 800 g; Stem length: 35 cm). The test panels were before the test during Stored for 24 hours at room temperature.

The flat hammer side was covered with a layer of steel wool and attached with Tesakrepp on the turned up sides. The hammer was Set at right angles to the clearcoats. The weight of the hammer was in a track on the without undetected and without additional physical strength surface the clearcoat led.

at every exam were 10 double strokes executed by hand. After each of these individual exams was exchanged the steel wool.

After loading, the test surfaces were cleaned with a soft cloth from the steel wool residues. The test areas were visually evaluated under artificial light and graded as follows: grade damage image 1 unavailable 2 low 3 moderate 4 moderate to medium 5 strongly 6 very strong

The Evaluation took place immediately after the end of the experiment.

The BART (BASF ACID RESISTANCE TEST) was used to determine the resistance of a clearcoat to acids, alkalis and water droplets. In this case, the clearcoat was exposed to a temperature load on a gradient oven after the incineration for 30 min at 40 ° C. Previously, the test substances (sulfuric acid 10%, 36%, sulfuric acid 6% strength, hydrochloric acid 10%, sodium hydroxide solution 5% strength, VE (= fully deionized or deionized) water-1,2, 3 or 4 drops) defined applied with a dosing pipette. Following the action of the substances, they were removed under running water and the damage was assessed visually after 24 h according to a predetermined scale: grading Appearance 0 no defect 1 slight mark 2 Marking / matting / no softening 3 Marking / Matting / Color change / Softening 4 Cracks / incipient etching 5 Clearcoat removed

It every single mark (spot) was evaluated and the result in the form of a note for each test substance recorded.

Furthermore, the AMTEC test was carried out according to DIN 67530 on the coating 2 with the following results (gloss at 20 °): Initial gloss: 88 Gloss after damage: after cleaning: 84, corresponds to 95.5% of the initial gloss Reflow time (min): 120 Reflow temperature (° C): 80 Shine after reflow: after cleaning: 83, corresponds to 94.3% of the initial gloss

Claims (11)

A coating composition based on aprotic solvents, containing (A) at least 50% by weight, based on the content of non-volatile substances in the coating composition, of at least one compound (A1) having at least one reactive group of the formula I. -NR-C (O) -N- (X-SiR "x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m (I) wherein R, = hydrogen, alkyl, cycloalkyl, aryl or aralkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, with Ra = alkyl, cycloalkyl, aryl or aralkyl, R '= hydrogen, alkyl or cycloalkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, X, X '= linear and / or branched alkylene or cycloalkylene radical having 2 to 20 carbon atoms, R "= alkyl, cycloalkyl, aryl or aralkyl, wherein the carbon chain may be interrupted by non-adjacent oxygen, sulfur or NRa groups, n = 0 to 2, m = 0 to 2, m + n + = 2, and x, y = 0 to 2 , (B) a catalyst for linking the -Si (OR ') 3-x (y) units, and (C) an aprotic solvent or a mixture of aprotic solvents. Coating composition according to Claim 1, characterized that X and / or X 'for alkylene with 2 to 4 carbon atoms. Coating composition according to Claims 1 or 2, characterized in that component (A1) is obtained by reacting at least one polyisocyanate PI with at least one aminosilane of the formula II: HN- (X-SiR "x (OR ') 3-x) n (X'-SiR''y (OR') 3-y) m (II) will be produced. Coating composition according to Claim 3, characterized that at the reaction of the polyisocyanate PI with the aminosilanes (II) at least 90 mol% of the isocyanate groups of the polyisocyanate PI to structural units (I) be implemented. Coating composition according to claim 3 or 4, characterized characterized in that Polyisocyanate PI selected is from the group 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-methylenedicyclohexyl diisocyanate, the biuret dimers of the aforementioned polyisocyanates and / or the Isocyanurate trimers of the aforementioned polyisocyanates. Coating composition according to one of claims 1 to 5, characterized in that the Katalaysator (B) from the group that of boron, aluminum, titanium and / or zirconium chelates, alcoholates and / or ester and / or selected from the group of nanoparticles Compounds of the elements aluminum, silicon, titanium and / or zirconium selected is. Coating composition according to one of claims 1 to 6, characterized in that the Catalyst (B) to 0.01 to 30 wt .-%, based on the content of nonvolatile Substances, in the coating agent, is present Coating composition according to one of claims 1 to 7, characterized in that the aprotic solvent (C) has a water content of not more than 1% by weight, based on the solvent. Coating composition according to one of claims 1 to 8, characterized in that in Coating composition in addition to component (A), (B) and (C) up to 40 wt .-%, based on the content of non-volatile substances, another Component (D) is included, which with the -Si (OR ') 3 groups of the component (A) and / or can form network points with itself. Coating composition according to Claim 9, characterized that the Component (D) is an aliphatic epoxy resin. Multi-stage coating process, characterized that on an optionally precoated substrate a pigmented basecoat film and then a layer of the coating agent according to one of claims 1 to 10 is applied.